Electronic DC dummy load
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- เผยแพร่เมื่อ 27 ก.ย. 2024
- Hi, Friends..
Here is a little Project which was on my list for a long time.
It is a simple but robust DC dummy load for load testing up to 50 Volts and 20 Amps...
I will post the circuit diagram to my pinterst and to my patreon profile..
Feel free, to become a Patreon and support me out here in the shop.
I will also post this video there, so you can watch it without adds..
Thanks for your support.
/ larifari
www.pinterest....
#dummy load #homemade dummy load #DC dummyload DIY
Awesome project! Won't you need a low pass filter to smooth the PWM pulses to apply a constant load rather than a pulsed load? Thanks
Yes..The 100nF cap parallel to the 1 Ohm resistor and the 220µF electrolythic cap between the two input terminals are in the circuit to do just that...providing at least a crude filtering..It keeps the circuit simple and does the job.. Maybe i will build another version of the thing..A pure linear load.. Using a operational amp instead of the PWM / 555 Timer... And the circuit would be even simpler than the PWM version..
I love this guy already! What a professional job! Cheer!
it will be inductive
Nice build and neatly done mate... The build quality and feel of it, and how you filmed the process... Just for this alone you deserve way more views. I wish I had more space to build my propper workshop xD And ofc... I love the resistor... question... maybe you mentioned it but what did you use as isolator (the part where you wrapped the wire onto) and also... what type of wire is that ? Thanks
These are left over strips of floor tiles. But you could use any ceramic material.. The wire is just ordenary steel fence wire. 1,2 mm thick...as far as i remember.. Since then, i moved to another place, which is better suited for my filming and my work in general.. I am in the process of building a new workshop.. You can follow me on instagram.. Maybe you can rent a cheap place and renovate it? Having a nice and tidy workshop is mans therapy room. :D My personal slogan : "In a workshop that you are proud of, things are created that you are proud of"
You did a great job. Can you please tell me what kind of wire did you used for the power resistor? Thanks.
Yes.. It is a 1,6 mm galvanized steel fence wire... Just ordenary fence wire.... from the farmers supply shop. ;) I winded it around a strip of floor tile...
pwm in a purely linear utility? Why not operational? In tests, individual control of each mosfet and not placing them in parallel gives better performance.
If i would need something with better performance, i would by a propper dummy load... But i need it just occationally and just for "primitive" load testing.. In the past decades, i did all my load testing with incadecent light bulbs or resistors in series or parallel. Just for simple stuff... To see if a component or heatsink gets to hot...something like this... I am not an expert.. I am an uneducated hobbyist... So, yeah, a device which is adjustable and shows me volts and amps is by far good enough for me... I am an artist and tinkerer, not a professional by any means.. I build stuff with materials i have laying around and even trash.. With limited knowledge and very little money and time on hand..... Greets from austria.
thanks for the reply. The idea of manufacturing resistance is interesting, I expropriate it. Greetings
Hallo. You did a fantastic job, with yours new workshop.... and also with this dummy load.
How much power and maximum amperage can your load handle?
I have 2 Dell server power supplies that I want to conect in series. That's how I get 24V and 54A, so approx. 1300w.
What kind of adjustment do I need to make to your schematic for that power? maybe more mosfets? How many mosfets can be add to be turned on at the same time by IC555 circuit without any driver ?
I built a mosfet bank with 12 of this irfz 44N some years ago. It worked well and could handle more than 100A with ease..
It was a PWM driver for a 24 Volt DC hydraulic Motor / pump..
The output of the 555 Timer is able to deliver 200 mA...
Do you want to test your frankenstein power supply with such a homemade dummy load?
@@LariFariTH-cam yes, the power supply label says 12V/ 54.4 A. I have 2 power supplies that are the same, I plan to connect in series. I like to check if the tte labels are real or are amps from China. For one of the power supplies you have to "floating ground", but that's another discussion.
I'll probably never use that kind of powersupply to power anything at this amperage, but....that's the essence of DIY, to make things that aren't necessary
I like your style. That DIY power resistor is killer, and you have assembled what looks to be a robust, functional circuit. I've been looking at commercial units, which can be a bit pricey (especially those made by reputable manufacturers whose specs can be trusted), but my junk box has almost all the parts needed to build my own. Thanks for sharing your work.
Te ha quedado muy bien. Parece comercial. Y con estilo retro. Me gusta que hayas añadido medidor de voltaje y amperaje analógico. Estaba mirando de comprar una carga electrónica de Aliexpress, o hacer una tipo DIY. Y tras ver tu video, me he decidido por hacer una tipo DIY como la que tú has hecho en el vídeo. Enhorabuena, buen vídeo, sigue así!
Es cierto que me gusta la que has hecho. Lo unico, para mi sitio de trabajo, es bastante grande. Entonces, seguiré mirando opciones en internet. O quizá haga la misma, pero con menos transistores en la salida, y resistencia de carga, más compacta. Gracias
Ah, por supuesto, también puedes hacer el dispositivo más pequeño, con menos piezas. No tienes que exagerar como lo hice yo. Mi dispositivo puede "calentar" 1500 vatios... al menos durante un corto período de tiempo. También existe la opción de "simplemente" usar un mosfet en un disipador de calor. Opera el Mosfet en el "rango lineal". Todo está controlado por un amplificador operacional. También es una construcción bastante simple. Completamente sin PWM. Hay muchos diagramas de circuitos en Internet. Busque "carga ficticia lineal". Tal vez haga un video sobre esto. Si no encuentras nada adecuado, puedes contactarme en Instagram y te enviaré un diagrama del circuito. Saludos desde Austria.
Exelente trabalho parabéns
I love your very creative DIY thinking and execution!!! Please tell us what type of concrete did you use for the mounts? I did not see any aggregate/rocks. A few things to consider... Thermal expansion may crack the blocks, over time. Next time, maybe do not run the wire into the concrete... Galvanized fence wire will emit rather toxic fumes, when heated. Maybe run it outside to burn off the coating, before using it in your shop. I had already been thinking of using concrete with my dim bulb limiter... I need a switch panel and having a proper, custom one manufactured is expensive. So, I thought of making one out of concrete, in the same manner as custom counter tops. I have already built the form, but I have never poured the concrete... Mostly, because I am not sure how it will hold up, being only about 1/2" thick. What do you think? Amazing shop. Amazing skills. Amazing build.
It is not concrete in that sense.. It is what we over here in Austria call " Flexkleber". It is a kind of cement to put wall or floor tiles on. Especially for outside use or where walls and floor vibrate a lot...This stuff has the look and feel of concrete, once cured, but is somewhat flexible. It is ment to be used outside for patio pavement , radiant floor heating and such things. From minus 40 to plus 60 degrees. With no cracks and damage. You can mix it with sand or grabbel, if needed...I think, this could be the right choice for your dim bulb / current limiter. Even thogh, i built mine out of sheet metal.. Speaking of toxic fumes.. I never drive the wire to a point, where the zinc could be emitted.. And even then, i dont care. I was half of my life a industrial machine fitter and steel worker and made some kilometers of weld on galvanized Steel. There was a lot of very nasty, white toxic fume... Thats the reality of hard working men... I am not expecting to live very long.
Wery nice job😊